Retrogradation inhibition of rice starch with dietary fiber from extruded and unextruded rice bran

Abstract

This study aims to investigate the gelatinization and retrogradation behavior of rice starch with the addition of soluble and insoluble dietary fiber from extruded rice bran (ES, EI) compared to that from un-extruded rice bran (UES, UEI). Differential scanning calorimetry (DSC), X-ray diffraction (XRD), texture profile analysis (TPA) and scanning electron microscopy (SEM) were used for investigation. As the amount of dietary fiber increased (0%, 4%, 8%, 16%, 20%), the gelatinization temperature increased, while the values of setback and breakdown decreased. Both ES and EI showed weaker inhibition on short-term staling of rice starch than UES and UEI, respectively. The results confirmed that the dietary fiber from rice bran exhibited suppression of long-term staling of rice starch, and the inhibition abilities of ES and EI at the same concentration were higher than that of UES and UEI, respectively. It may be useful for the utilization of dietary fiber from extruded rice bran for preventing rice starch staling and quality improvement of rice products.